Commit a4072543 has changed the I/O here
from working on a local one-element I/O vector to just using the buffer
directly (using the bdrv_co_pread()/bdrv_co_pwrite() helper functions
introduced shortly before).

However, it only changed the bdrv_co_preadv() call to bdrv_co_pread() -
the subsequent bdrv_co_pwritev() call stayed this way, and so still
expects a QEMUIOVector pointer instead of a plain buffer.  We must
change that to be a bdrv_co_pwrite() call.

Fixes: a4072543 ("block/parallels: use buffer-based io")
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220714132801.72464-2-hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>